When using the Internet, it is desirable for a user to be identified by a specific Internet Protocol (IP) address. This helps with the identification of illegal traffic or activities that are a danger to national security, for example. However, if a user is connected to the Internet via a public Ethernet network, the identification of users becomes more difficult, as in a standard network there are no technical barriers against a user changing both his IP-address and MAC-address, an activity commonly referred to as “spoofing”. The term “Public Ethernet” designates an Ethernet network in which the core network is composed of self-learning switches or nodes forming an aggregated network. Switching through the aggregated network is accomplished using the destination media access control (MAC) address of packets, with each node gradually associating MAC addresses with the associated destination addresses as they receive and redirect packets. This may be accomplished using address resolution protocol (ARP) requests to an edge node or router in the network each time a switch in the aggregate network receives a packet with a new MAC address.
It is possible to impose a user identification within an Ethernet access network, wherein each subscriber is required to use a unique username and password to login before being awarded access to the network, such as imposed by the point-to-point protocol PPPoE. However, such systems are not always appreciated as the need to login each time inevitably slows the access. A further technical solution in such a shared media consists of routing all traffic between all users. However, this is expensive and inefficient. The access nodes must be capable of routing all traffic and each user is effectively assigned at least one IP-subnet, which generally includes four IP-addresses, regardless of the number of IP-addresses required. When such restrictions on the configuration of or routing within the Ethernet access network are not present, security within the network is reliant on mutual trust and on all users following administration rules.
In the light of this prior art, it is thus an object of the present invention to increase the security over an Ethernet access network without imposing restrictions on the configuration or routing within the network itself.